A study in which neither the participants nor the experimenters know who is receiving the test treatment(s) or placebo.
The double-blind study design is used to minimize participant and researcher biases that could threaten the validity of a research study.
Randomized double blind placebo control studies, the “Gold Standard” in intervention based studies (Indian Journal of Sexually Transmitted Diseases and AIDS, 2012)
GRADE guidelines: 4. Rating the quality of evidenced study limitations (risk of bias) (Journal of Clinical Epidemiology, 2011)
Video: Blinding in Randomised Controlled Trials (Coursera, 2019)